Preheat oven to 350 degrees F. Lightly butter a 9-inch square baking pan.
In a large bowl, combine dates, walnuts, flour, baking powder, sugar, and eggs. Spread mixture onto bottom of prepared baking pan.
Bake 35 minutes; remove from oven and let cool on a wire rack for 15 minutes. Cut into squares.
Toss warm squares, a few at a time, in the powdered sugar. Transfer to a wire rack to cool completely. Sprinkle with more powdered sugar just before serving.
Storage: Date Squares keep, layered between sheets of wax paper or parchment paper, in an airtight container at room temperature for approximately 1 week. These cookies also freeze well.
Date Squares Recipe - Matrimonial Bars Recipe: https://whatscookingamerica.net/cookie/datesquares.htm